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MNLP_M2_mcqa_dataset

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What do living things need to survive?
sciq_209
A) nutrients B) molecules C) oxygen D) heat
A) nutrients
There are three main ocean zones based on distance from shore. They are the intertidal zone , neritic zone , and oceanic zone . Distance from shore influences how many nutrients are in the water. Why? Most nutrients are washed into ocean water from land. Therefore, water closer to shore tends to have more nutrients. Living things need nutrients. So distance from shore also influences how many organisms live in the water.
SciQ
The denser regions of the electron cloud are called what?
sciq_210
A) cores B) orbitals C) lattices D) isotopes
B) orbitals
Some regions of the electron cloud are denser than others. The denser regions are areas where electrons are most likely to be. These regions are called orbitals . Each orbital has a maximum of just two electrons. Different energy levels in the cloud have different numbers of orbitals. Therefore, different energy levels have different maximum numbers of electrons. Table below lists the number of orbitals and electrons for the first four energy levels. Energy levels farther from the nucleus have more orbitals. Therefore, these levels can hold more electrons.
SciQ
In studying energy, what term do scientists use to refer to the matter and its environment involved in energy transfers?
sciq_211
A) world B) ecosystem C) system D) molecule
C) system
6.3 The Laws of Thermodynamics In studying energy, scientists use the term “system” to refer to the matter and its environment involved in energy transfers. Everything outside of the system is called the surroundings. Single cells are biological systems. Systems can be thought of as having a certain amount of order. It takes energy to make a system more ordered. The more ordered a system is, the lower its entropy. Entropy is a measure of the disorder of a system. As a system becomes more disordered, the lower its energy and the higher its entropy become. A series of laws, called the laws of thermodynamics, describe the properties and processes of energy transfer. The first law states that the total amount of energy in the universe is constant. This means that energy can’t be created or destroyed, only transferred or transformed. The second law of thermodynamics states that every energy transfer involves some loss of energy in an unusable form, such as heat energy, resulting in a more disordered system. In other words, no energy transfer is completely efficient and tends toward disorder.
SciQ
To measure what changes that occur in chemical reactions, chemists usually use a related thermodynamic quantity, calledenthalpy?
sciq_212
A) entropy B) ion exchange C) evaporation D) energy
D) energy
(a) Initially, the system (a copper penny and concentrated nitric acid) is at atmospheric pressure. (b) When the penny is added to the nitric acid, the volume of NO2 gas that is formed causes the piston to move upward to maintain the system at atmospheric pressure. In doing so, the system is performing work on its surroundings. The symbol E in represents the internal energy of a system, which is the sum of the kinetic energy and potential energy of all its components. It is the change in internal energy that produces heat plus work. To measure the energy changes that occur in chemical reactions, chemists usually use a related thermodynamic quantity calledenthalpy (H) (from the Greek enthalpein, meaning “to warm”). The enthalpy of a system is defined as the sum of its internal energy E plus the product of its pressure Pand volume V:.
SciQ
What is a species that plays an especially important role in it's community called?
sciq_213
A) complement B) Invasive C) Leader D) keystone
D) keystone
Some predator species are known as keystone species. A keystone species is one that plays an especially important role in its community. Major changes in the numbers of a keystone species affect the populations of many other species in the community. For example, some sea star species are keystone species in coral reef communities. The sea stars prey on mussels and sea urchins, which have no other natural predators. If sea stars were removed from a coral reef community, mussel and sea urchin populations would have explosive growth. This, in turn, would drive out most other species. In the end, the coral reef community would be destroyed.
SciQ
What term that shows how fast a population is growing includes new members added to the population over a given period, as well as old members removed from the population?
sciq_214
A) birth rate B) growth rate C) emigration D) population density
B) growth rate
The population growth rate is how fast a population is growing. The letter r stands for the growth rate. The growth rate equals the number of new members added to the population in a year for each 100 members already in the population. The growth rate includes new members added to the population and old members removed from the population. Births add new members to the population. Deaths remove members from the population. The formula for population growth rate is:.
SciQ
The rings of what planet can be easily seen from earth?
sciq_215
A) saturn B) Venus C) Neptune D) jupiter
A) saturn
All of the outer planets have numerous moons. They also have planetary rings made of dust and other small particles. Only the rings of Saturn can be easily seen from Earth.
SciQ
What planet is a blue green color?
sciq_216
A) uranus B) Mercury C) Mars D) sirius
A) uranus
Uranus is a lot like Jupiter and Saturn. The planet is composed mainly of hydrogen and helium. There is a thick layer of gas on the outside. Further on the inside is liquid. But Uranus has a higher percentage of icy materials than Jupiter and Saturn. These materials include water, ammonia, and methane. Uranus is also different because of its blue-green color. Clouds of methane filter out red light. This leaves a blue-green color. The atmosphere of Uranus has bands of clouds. These clouds are hard to see in normal light. The result is that the planet looks like a plain blue ball.
SciQ
The simplest class of organic compounds is the what?
sciq_217
A) Phenols B) particles C) hydrocarbons D) gas
C) hydrocarbons
isolating the individual components, preservationists are better able to determine the condition of an object and those books and documents most in need of immediate protection. The simplest class of organic compounds is the hydrocarbons, which consist entirely of carbon and hydrogen. Petroleum and natural gas are complex, naturally occurring mixtures of many different hydrocarbons that furnish raw materials for the chemical industry. The four major classes of hydrocarbons are the alkanes, which contain only carbon–hydrogen and carbon–carbon single bonds; the alkenes, which contain at least one carbon–carbon double bond; the alkynes, which contain at least one carbon–carbon triple bond; and the aromatic hydrocarbons, which usually contain rings of six carbon atoms that can be drawn with alternating single and double bonds. Alkanes are also called saturated hydrocarbons, whereas hydrocarbons that contain multiple bonds (alkenes, alkynes, and aromatics) are unsaturated.
SciQ
Some meteorites are made of iron and nickel and are thought to be very similar to what part of the earth?
sciq_218
A) mantel B) core C) crust D) shelf
B) core
Scientists study meteorites to learn about Earth’s interior. Meteorites formed in the early solar system. These objects represent early solar system materials. Some meteorites are made of iron and nickel. They are thought to be very similar to Earth's core ( Figure below ). An iron meteorite is the closest thing to a sample of the core that scientists can hold in their hands!.
SciQ
Which pathway carries somatosensory information from the face, head, mouth, and nasal cavity?
sciq_219
A) trigeminal pathway B) cranial pathway C) dual pathway D) posterior pathway
A) trigeminal pathway
The trigeminal pathway carries somatosensory information from the face, head, mouth, and nasal cavity. As with the previously discussed nerve tracts, the sensory pathways of the trigeminal pathway each involve three successive neurons. First, axons from the trigeminal ganglion enter the brain stem at the level of the pons. These axons project to one of three locations. The spinal trigeminal nucleus of the medulla receives information similar to that carried by spinothalamic tract, such as pain and temperature sensations. Other axons go to either the chief sensory nucleus in the pons or the mesencephalic nuclei in the midbrain. These nuclei receive information like that carried by the dorsal column system, such as touch, pressure, vibration, and proprioception. Axons from the second neuron decussate and ascend to the thalamus along the trigeminothalamic tract. In the thalamus, each axon synapses with the third neuron in its respective pathway. Axons from the third neuron then project from the thalamus to the primary somatosensory cortex of the cerebrum. The sensory pathway for gustation travels along the facial and glossopharyngeal cranial nerves, which synapse with neurons of the solitary nucleus in the brain stem. Axons from the solitary nucleus then project to the ventral posterior nucleus of the thalamus. Finally, axons from the ventral posterior nucleus project to the gustatory cortex of the cerebral cortex, where taste is processed and consciously perceived. The sensory pathway for audition travels along the vestibulocochlear nerve, which synapses with neurons in the cochlear nuclei of the superior medulla. Within the brain stem, input from either ear is combined to extract location information from the auditory stimuli. Whereas the initial auditory stimuli received at the cochlea strictly represent the frequency—or pitch—of the stimuli, the locations of sounds can be determined by comparing information arriving at both ears.
SciQ
The amount of kinetic energy in a moving object depends directly on its mass and what else?
sciq_220
A) volume B) density C) direction D) velocity
D) velocity
The amount of kinetic energy in a moving object depends directly on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. You can calculate the kinetic energy of a moving object with this equation:.
SciQ
Cycling, shoveling snow and cross-country skiing are examples of what kind of heart-strengthening activity?
sciq_221
A) metabolism B) anaerobic C) exercise D) aerobic
D) aerobic
When done regularly, aerobic activities, such as cycling, make the heart stronger. Other aerobic activities include mowing lawn, shoveling snow and cross country skiing.
SciQ
What take the shape of their container, and are relatively easy to compress?
sciq_222
A) molecules B) gases C) fluids D) semi-fluids
B) gases
The story is quite different for gases. Gases take the shape of their container, and they are relatively easy to compress. There are fewer gas particles per unit volume than for the same substance in the liquid or solid form. In fact, the liquid form of a given material is generally several hundred times more dense than the gas form at normal pressures. Despite the large amounts of empty space, a sample of a gas contains many particles moving around, colliding and imparting force on their surroundings. For example, in a one mole sample of gas at 0°C and 1 atm of pressure, each cubic centimeter contains roughly 2.7 × 10 19 molecules. Each molecule participates in several billion collisions every second, moving only about 10-100 nanometers between collisions. Additionally, these gas particles move at very high speeds. For example, at 25°C, the average speed of hydrogen molecules in a sample of hydrogen gas is 1960 m/s.
SciQ
What is moving air called?
sciq_223
A) humidity B) steam C) clouds D) wind
D) wind
Moving air, like moving water, causes erosion. Moving air is called wind.
SciQ
What is the name of the two metalloids in the carbon group called?
sciq_224
A) titantium and copper B) silicon and gold C) silver and gold D) silicon and germanium
D) silicon and germanium
Group 14 is called the carbon group. This group contains two metalloids: silicon and germanium. Carbon is a nonmetal, and the remaining elements in this group are metals.
SciQ
What is the name of the zone where water is deeper than 200 meters called?
sciq_225
A) transition zone B) eccentric zone C) euphotic zone D) aphotic zone
D) aphotic zone
The aphotic zone is water deeper than 200 meters. This is where too little sunlight penetrates for photosynthesis to occur. As a result, producers must make "food" by chemosynthesis , or the food must drift down from the water above.
SciQ
Diagnosing and treating cancer is a beneficial use of what potentially dangerous energy?
sciq_226
A) thermal B) radiation C) mechanical D) solar
B) radiation
Radiation has several important uses, including diagnosing and treating cancer.
SciQ
Many adults and some children suffer from a deficiency of lactase. these individuals are said to be lactose intolerant because they cannot digest the lactose found in what?
sciq_227
A) meat B) peanuts C) fruit D) milk
D) milk
Many adults and some children suffer from a deficiency of lactase. These individuals are said to be lactose intolerant because they cannot digest the lactose found in milk. A more serious problem is the genetic disease galactosemia, which results from the absence of an enzyme needed to convert galactose to glucose. Certain bacteria can metabolize lactose, forming lactic acid as one of the products. This reaction is responsible for the “souring” of milk.
SciQ
Catabolic reactions break down large organic molecules into smaller molecules, releasing the energy contained in what?
sciq_229
A) molecular bonds B) crystals bonds C) liquid bonds D) chemical bonds
D) chemical bonds
Catabolic Reactions Catabolic reactions break down large organic molecules into smaller molecules, releasing the energy contained in the chemical bonds. These energy releases (conversions) are not 100 percent efficient. The amount of energy released is less than the total amount contained in the molecule. Approximately 40 percent of energy yielded from catabolic reactions is directly transferred to the high-energy molecule adenosine triphosphate (ATP). ATP, the energy currency of cells, can be used immediately to power molecular machines that support cell, tissue, and organ function. This includes building new tissue and repairing damaged tissue. ATP can also be stored to fulfill future energy demands. The remaining 60 percent of the energy released from catabolic reactions is given off as heat, which tissues and body fluids absorb. Structurally, ATP molecules consist of an adenine, a ribose, and three phosphate groups (Figure 24.2). The chemical bond between the second and third phosphate groups, termed a high-energy bond, represents the greatest source of energy in a cell. It is the first bond that catabolic enzymes break when cells require energy to do work. The products of this reaction are a molecule of adenosine diphosphate (ADP) and a lone phosphate group (Pi). ATP, ADP, and Pi are constantly being cycled through reactions that build ATP and store energy, and reactions that break down ATP and release energy.
SciQ
In qualitative analysis, reagents are added to an unknown chemical mixture in order to induce what?
sciq_230
A) erosion B) motion C) precipitation D) sunlight
C) precipitation
Selective precipitation can also be used in qualitative analysis. In this method, reagents are added to an unknown chemical mixture in order to induce precipitation. Certain reagents cause specific ions to precipitate out; therefore, the addition of the reagent can be used to determine whether the ion is present in the solution.
SciQ
While climate change in earth history was due to natural processes, what is primarily to blame for recent global warming?
sciq_231
A) volcanos B) factories C) human actions D) wars
C) human actions
Climate change in Earth history was due to natural processes. Recent global warming is due mainly to human actions. The burning of fossil fuels releases greenhouse gases into the air. This creates greater greenhouse effect and global warming.
SciQ
What is the simplest life cycle?
sciq_232
A) metamorphic cycle B) diploid life cycle C) binary life cycle D) haploid life cycle
D) haploid life cycle
The haploid life cycle ( Figure below ) is the simplest life cycle. It is found in many single-celled organisms. Organisms with a haploid life cycle spend the majority of their lives as haploid gametes. When the haploid gametes fuse, they form a diploid zygote. It quickly undergoes meiosis to produce more haploid gametes that repeat the life cycle.
SciQ
What keeps the moon orbiting earth?
sciq_233
A) the Sun B) gravity C) Coriolis effect D) axial tilt
B) gravity
Gravity keeps the Moon orbiting Earth. Gravity keeps the planets orbiting the Sun.
SciQ
What are formed by the attraction between oppositely charged ions?
sciq_234
A) ionic bonds B) soluble bonds C) inept bonds D) magnetic bonds
A) ionic bonds
Ionic bonds are formed by the attraction between oppositely charged ions.
SciQ
What produces hormones that directly regulate body processes?
sciq_235
A) lymph glands B) pancreas C) hippocampus D) hypothalamus
D) hypothalamus
The hypothalamus also produces hormones that directly regulate body processes. For example, it produces antidiuretic hormone. This hormone travels to the kidneys and stimulates them to conserve water by producing more concentrated urine.
SciQ
Comparing anatomy, and characterizing the similarities and differences, provides evidence of what process?
sciq_236
A) emergence B) evolution C) regression D) devolution
B) evolution
Take a close look at this gorilla hand. The similarities to a human hand are remarkable. Comparing anatomy, and characterizing the similarities and differences, provides evidence of evolution.
SciQ
What is the second most abundant element in the earth's crust?
sciq_237
A) helium B) carbon C) nitrogen D) silicon
D) silicon
What is this intricate orb? It is the greatly magnified skeleton of single-celled ocean organisms call radiolarian. The skeleton is made of an element that is extremely common on Earth. In fact, it is the second most abundant element in Earth’s crust. It is also one of the most common elements in the entire universe. What is this important element? Its name is silicon, and it belongs to a class of elements called metalloids.
SciQ
More than half of all known organisms are what?
sciq_239
A) mammals B) insects C) spiders D) enzymes
B) insects
The majority of arthropods are insects (Class Insecta). In fact, more than half of all known organisms are insects. There may be more than 10 million insect species in the world, although most of them have not yet been identified. In terms of their numbers and diversity, insects clearly are the dominant animals in the world.
SciQ
Saturn is made mostly of helium and what else?
sciq_241
A) nitrogen B) carbon C) hydrogen D) hydrogen
C) hydrogen
Saturn’s composition is similar to Jupiter's. The planet is made mostly of hydrogen and helium. These elements are gases in the outer layers and liquids in the deeper layers. Saturn may also have a small solid core. Saturn's upper atmosphere has clouds in bands of different colors. These clouds rotate rapidly around the planet. But Saturn has fewer storms than Jupiter. Thunder and lightning have been seen in the storms on Saturn ( Figure below ).
SciQ
What are alkenes organic compounds that contain one or more double or triple bonds between carbon atoms described as?
sciq_242
A) insulated B) strong C) saturated D) unsaturated
D) unsaturated
Alkenes Organic compounds that contain one or more double or triple bonds between carbon atoms are described as unsaturated. You have likely heard of unsaturated fats. These are complex organic molecules with long chains of carbon atoms, which contain at least one double bond between carbon atoms. Unsaturated hydrocarbon molecules that contain one or more double bonds are called alkenes. Carbon atoms linked by a double bond are bound together by two bonds, one σ bond and one π bond. Double and triple bonds give rise to a different geometry around the carbon atom that participates in them, leading to important differences in molecular shape and properties. The differing geometries are responsible for the different properties of unsaturated versus saturated fats. Ethene, C2H4, is the simplest alkene. Each carbon atom in ethene, commonly called ethylene, has a trigonal planar structure. The second member of the series is propene (propylene) (Figure 20.7); the butene isomers follow in the series. Four carbon atoms in the chain of butene allows for the formation of isomers based on the position of the double bond, as well as a new form of isomerism.
SciQ
Electrons in covalent compounds are shared between the two atoms, unlike the case in what type of bonds?
sciq_243
A) horizontal bonds B) ionic bonds C) soluble bonds D) weak bonds
B) ionic bonds
The two materials do have at least one thing in common. The atoms in the materials are held together by covalent bonds. These bonds consist of electrons shared between two or more atoms. Unlike ionic bonds, where electrons are either lost or gained by an atom to form charged ions, electrons in covalent compounds are shared between the two atoms, giving rise to properties that are quite different from those seen in ionic materials.
SciQ
What is the resistance of a liquid to flow called?
sciq_244
A) elasticity B) viscosity C) turbulence D) permeability
B) viscosity
Viscosity (η) is the resistance of a liquid to flow. Some liquids, such as gasoline, ethanol, and water, flow very readily and hence have a low viscosity. Others, such as motor oil, molasses, and maple syrup, flow very slowly and have a high viscosity. The two most common methods for evaluating the viscosity of a liquid are (1) to measure the time it takes for a quantity of liquid to flow through a narrow vertical tube and (2) to measure the time it takes steel balls to fall through a given volume of the liquid. The higher the viscosity, the slower the liquid flows through the tube and the steel balls fall. Viscosity is expressed in units of the poise (mPa·s); the higher the number, the higher the viscosity. The viscosities of some representative liquids are listed in Table 11.4 "Surface Tension, Viscosity, Vapor Pressure (at 25°C Unless Otherwise Indicated), and Normal Boiling Points of Common Liquids" and show a correlation between viscosity and intermolecular forces. Because a liquid can flow only if the molecules can move past one another with minimal resistance, strong intermolecular attractive forces make it more difficult for molecules to move with respect to one another. The addition of a second hydroxyl group to ethanol, for example, which produces ethylene glycol (HOCH2CH2OH), increases the viscosity 15-fold. This effect is due to the increased number of hydrogen bonds that can form between hydroxyl groups in adjacent molecules, resulting in dramatically stronger intermolecular attractive forces.
SciQ
The mass of atoms is based on the number of protons and neutrons in what?
sciq_245
A) nucleus B) components C) molecules D) electrons
A) nucleus
Atoms have a mass that is based largely on the number of protons and neutrons in their nucleus.
SciQ
Where do polychaete worms live?
sciq_246
A) in tide pools B) the ocean floor C) in coral reefs D) attached to marine life
B) the ocean floor
Annelids called polychaete worms live on the ocean floor. They may be filter feeders, predators, or scavengers. The amazing feather duster worm in Figure below is a polychaete that has a fan-like crown of tentacles for filter feeding.
SciQ
What is the study of how and why plants and animals live where they do?
sciq_247
A) biogeography B) heredity C) geomorphology D) lithography
A) biogeography
Biogeography is the study of how and why plants and animals live where they do. It provides more evidence for evolution. Let’s consider the camel family as an example.
SciQ
Muscles that position the pectoral girdle are located either on the anterior thorax or on this?
sciq_248
A) inferred thorax B) posterior thorax C) posterior thorax D) analogous thorax
B) posterior thorax
Muscles That Position the Pectoral Girdle Muscles that position the pectoral girdle are located either on the anterior thorax or on the posterior thorax (Figure 11.22 and Table 11.8). The anterior muscles include the subclavius, pectoralis minor, and serratus anterior. The posterior muscles include the trapezius, rhomboid major, and rhomboid minor. When the rhomboids are contracted, your scapula moves medially, which can pull the shoulder and upper limb posteriorly.
SciQ
What are the two major types of seed plants called?
sciq_249
A) perennials and annuals B) deciduous and evergreen C) gymnosperms and angiosperms D) flowers and fruits
C) gymnosperms and angiosperms
The two major types of seed plants are the gymnosperms (seeds in cones) and angiosperms (seeds in ovaries of flowers). Figure below shows how the seeds of gymnosperms and angiosperms differ. Do you see the main difference between the two seeds? The angiosperm seed is surrounded by an ovary .
SciQ
What do we call the energy-rich product of photosynthesis?
sciq_250
A) chloride B) glucose C) sugar D) insulin
B) glucose
Glucose is the energy-rich product of photosynthesis, a universal food for life. It is also the primary form in which your bloodstream delivers energy to every cell in your body.
SciQ
How is oxygen transferred into the bloodstream?
sciq_251
A) hard diffusion B) brain diffusion C) mean diffusion D) simple diffusion
D) simple diffusion
The oxygen enters the bloodstream from the alveoli , tiny sacs in the lungs where gas exchange takes place ( Figure below ). The transfer of oxygen into the blood is through simple diffusion.
SciQ
Ringworm and athlete's foot are human diseases caused by what simple organisms?
sciq_252
A) insects B) bacteria C) viruses D) fungi
D) fungi
Fungi are simple eukaryotic organisms that consist of one or more cells. They include mushrooms and yeasts. Human diseases caused by fungi include ringworm and athlete’s foot. Both are skin diseases that are not usually serious. A ringworm infection is pictured below ( Figure below ). A more serious fungus disease is histoplasmosis. It is a lung infection. Though fungal infections can be annoying, they are rarely as serious or deadly as bacterial or viral infections.
SciQ
What is the measure of the change in the velocity of a moving object called?
sciq_253
A) transmission B) pressurization C) acceleration D) compression
C) acceleration
A car’s gas pedal, like the one in Figure below , is sometimes called the accelerator. That’s because it controls the acceleration of the car. Pressing down on the gas pedal gives the car more gas and causes the car to speed up. Letting up on the gas pedal gives the car less gas and causes the car to slow down. Whenever an object speeds up, slows down, or changes direction, it accelerates. Acceleration is a measure of the change in velocity of a moving object. Acceleration occurs whenever an object is acted upon by an unbalanced force.
SciQ
What is the usual treatment for acute bronchitis?
sciq_254
A) surgery B) physical therapy C) pesticides D) antibiotics
D) antibiotics
Bronchitis is an inflammation of the bronchi, the air passages that conduct air into the lungs. The bronchi become red and swollen with infection. Acute bronchitis is usually caused by viruses or bacteria, and may last several days or weeks. It is characterized by a cough that produces phlegm, or mucus. Symptoms include shortness of breath and wheezing. Acute bronchitis is usually treated with antibiotics.
SciQ
What are generally divided into prosimian and non-prosimian?
sciq_255
A) primates B) insects C) rodents D) carnivores
A) primates
Primates are generally divided into prosimian and non-prosimian primates.
SciQ
The creation and destruction of oceanic crust is the reason what moves?
sciq_256
A) oceans B) continents C) animals D) planets
B) continents
In some places, the oceanic crust comes up to a continent. The moving crust pushes that continent away from the ridge axis as well. If the moving oceanic crust reaches a deep sea trench, the crust sinks into the mantle. The creation and destruction of oceanic crust is the reason that continents move.
SciQ
What is the concept by which two species within the same area to coexist by adapting by developing different specializations?
sciq_257
A) character concept B) character development C) feature displacement D) character displacement
D) character displacement
Looking at different types of competition, ecologists developed the competitive exclusion principle . The principle states that species less suited to compete for resources will either adapt, move from the area, or die out. In order for two species within the same area to coexist, they may adapt by developing different specializations. This is known as character displacement . An example of character displacement is when different birds adapt to eating different types of food. They can develop different types of bills, like Darwin’s Finches ( Figure below ). Therefore, competition for resources within and between species plays an important role in evolution through natural selection .
SciQ
A turbine that spins a generator will produce?
sciq_258
A) electricity B) light C) magnetic fields D) solar energy
A) electricity
You can follow the operation of an electricity-generating fission reactor in the image above. The reactor core is submerged in a pool of water. The heat from the fission reaction heats the water, which is pumped into a heat exchange container. There the heated water boils the water in the heat exchanger. The produced steam is forced through a turbine that spins a generator and produces electricity. After the water passes through the turbine, it is condensed back to liquid water and pumped back to the heat exchanger.
SciQ
In this type of reaction, an element replaces another element in a compound, and the element is in any state of matter but is not an ion?
sciq_259
A) polar reaction B) replication reaction C) double-replacement reaction D) single-replacement reaction
D) single-replacement reaction
A single-replacement reaction is one in which an element replaces another element in a compound. An element is in either the solid, liquid, or gas state and is not an ion. The example below shows the reaction of solid magnesium metal with aqueous silver nitrate to form aqueous magnesium nitrate and silver metal.
SciQ
What category of elements are chacterized by their ability to reflect light, called luster, their high electrical and thermal conductivity, their high heat capacity, and their malleability and ductility?
sciq_260
A) metals B) nonmetals C) noble gases D) halogens
A) metals
Metallic Solids Metals are characterized by their ability to reflect light, called luster, their high electrical and thermal conductivity, their high heat capacity, and their malleability and ductility. Every lattice point in a pure metallic element is occupied by an atom of the same metal. The packing efficiency in metallic crystals tends to be high, so the resulting metallic solids are dense, with each atom having as many as 12 nearest neighbors. Bonding in metallic solids is quite different from the bonding in the other kinds of solids we have discussed. Because all the atoms are the same, there can be no ionic bonding, yet metals always contain too few electrons or valence orbitals to form covalent bonds with each of their neighbors. Instead, the valence electrons are delocalized throughout the crystal, providing a strong cohesive force that holds the metal atoms together.
SciQ
Angiosperms are also known as what?
sciq_261
A) flowering plants B) dry plants C) dead plants D) uncommon plants
A) flowering plants
Introduction Plants are as essential to human existence as land, water, and air. Without plants, our day-to-day lives would be impossible because without oxygen from photosynthesis, aerobic life cannot be sustained. From providing food and shelter to serving as a source of medicines, oils, perfumes, and industrial products, plants provide humans with numerous valuable resources. When you think of plants, most of the organisms that come to mind are vascular plants. These plants have tissues that conduct food and water, and they have seeds. Seed plants are divided into gymnosperms and angiosperms. Gymnosperms include the needle-leaved conifers—spruce, fir, and pine—as well as less familiar plants, such as ginkgos and cycads. Their seeds are not enclosed by a fleshy fruit. Angiosperms, also called flowering plants, constitute the majority of seed plants. They include broadleaved trees (such as maple, oak, and elm), vegetables (such as potatoes, lettuce, and carrots), grasses, and plants known for the beauty of their flowers (roses, irises, and daffodils, for example). While individual plant species are unique, all share a common structure: a plant body consisting of stems, roots, and leaves. They all transport water, minerals, and sugars produced through photosynthesis through the plant body in a similar manner. All plant species also respond to environmental factors, such as light, gravity, competition, temperature, and predation.
SciQ
An estimated 100 trillion of these live in the gut of an average person?
sciq_262
A) viruses B) algae C) pathogens D) bacteria
D) bacteria
It is estimated that 100 trillion bacteria live in the gut. This is more than the human cells that make up you. It has also been estimated that there are more bacteria in your mouth than people on the planet. There are over 7 billion people on the planet.
SciQ
The ability to regulate what, which is possessed by mammals, was an advantage as earth’s climate went through sudden and dramatic changes?
sciq_263
A) reflex behaviors B) hair growth C) body temperature D) mutations
C) body temperature
Mammals have the ability to regulate body temperature. This is an advantage, as Earth’s climate went through sudden and dramatic changes. Mastodons, saber tooth tigers, hoofed mammals, whales, primates and eventually humans all lived during the Cenozoic Era ( Figure below ).
SciQ
What is the term for very large arrays of tandemly repeating, non-coding dna?
sciq_264
A) satellite dna B) recombinant dna C) models dna D) addition dna
A) satellite dna
The majority of the human genome is non-coding sequence. These sequences include regulatory sequences, and DNA with unknown functions. These sequences include tandem repeat elements known as satellite DNA , and transposons. Satellite DNA consists of very large arrays of tandemly repeating, non-coding DNA. The repeating units can be just a single base (a mono nucleotide repeat), two bases (a dinucleotide repeat), three bases (a trinucleotide repeat) or a much larger repeating unit. Some repeating units are several thousand base pairs long, and the total size of a satellite DNA segment can be several megabases without interruption.
SciQ
What kind of map can show the features of the bottom of a body of water?
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A) country B) topographic C) basic D) bathymetric
D) bathymetric
Oceanographers use bathymetric maps to show the features of the bottom of a body of water.
SciQ
What evolved, adapted response to resource availability is the long-range seasonal movement of animals?
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A) migration B) changing C) Stagnation D) regulating
A) migration
Migration Migration is the long-range seasonal movement of animals. It is an evolved, adapted response to variation in resource availability, and it is a common phenomenon found in all major groups of animals. Birds fly south for the winter to get to warmer climates with sufficient food, and salmon migrate to their spawning grounds. The popular 2005 documentary March of the Penguins followed the 62-mile migration of emperor penguins through Antarctica to bring food back to their breeding site and to their young. Wildebeests (Figure 45.35) migrate over 1800 miles each year in search of new grasslands.
SciQ
What is another name for composite volcanos?
sciq_267
A) seismic giants B) fjords C) fault lines D) stratovolcanoes
D) stratovolcanoes
Composite volcanoes are also called stratovolcanoes. This is because they are formed by alternating layers (strata) of magma and ash ( Figure below ). The magma that creates composite volcanoes tends to be thick. The steep sides form because the lava cannot flow too far from the vent. The thick magma may also create explosive eruptions. Ash and pyroclasts erupt into the air. Much of this material falls back down near the vent. This creates the steep sides of stratovolcanoes. The composition of magma that erupts at composite volcanoes is usually felsic (rhyolite) or intermediate (andesite).
SciQ
Fossil records support the idea that periods of little change may be interrupted by bursts of rapid change, an evolutionary model contrasted by what?
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A) elitism B) minimalism C) gradualism D) darwinian
C) gradualism
When geologic and climatic conditions are changing, evolution may occur more quickly. Thus, long periods of little change may be interrupted by bursts of rapid change. This model of the timing of evolution is called punctuated equilibrium . It is better supported by the fossil record than is gradualism.
SciQ
What type of winds occur when air is forced over a mountain range?
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A) trade winds B) doldrums C) local winds D) chinook winds
D) chinook winds
Chinook winds ( Figure below ) occur when air is forced over a mountain range. Warm air rises over the Sierra Nevada in California, for example, because it is pushed eastward by the westerly winds. The air cools as it rises and precipitates. The air is now dry. It sinks down the far side of the mountains and may create strong winds. These Chinook winds are relatively warm. If there is snow, the winds may melt it quickly. The dry sinking air creates a rainshadow effect . Rainshadow effect is responsible for many of the world's deserts.
SciQ
What do clouds trap into the atmosphere at night?
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A) smog B) seawater C) heat D) light
C) heat
Clouds block sunlight in the day. Clouds trap heat in the atmosphere at night.
SciQ
A nerve cell that carries messages is called a?
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A) mitochondria B) stem cell C) platelet D) neuron
D) neuron
The nervous system is made up of nerves. A nerve is a bundle of nerve cells. A nerve cell that carries messages is called a neuron. The messages carried by neurons are called nerve impulses.
SciQ
What group of animals are the largest arthropods?
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A) birds B) insects C) spiders D) fish
B) insects
There are several traits shared by all arthropods. Arthropods have a complete digestive system. They also have a circulatory system and a nervous system. In addition, they have special organs for breathing and excreting wastes. Other traits of arthropods include:.
SciQ
What term describes a collection of similar cells that had a common embryonic origin?
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A) organ-level organization B) plasma C) tissue D) nucleus
C) tissue
Complex Tissue Structure A hallmark trait of animals is specialized structures that are differentiated to perform unique functions. As multicellular organisms, most animals develop specialized cells that group together into tissues with specialized functions. A tissue is a collection of similar cells that had a common embryonic origin. There are four main types of animal tissues: nervous, muscle, connective, and epithelial. Nervous tissue contains neurons, or nerve cells, which transmit nerve impulses. Muscle tissue contracts to cause all types of body movement from locomotion of the organism to movements within the body itself. Animals also have specialized connective tissues that provide many functions, including transport and structural support. Examples of connective tissues include blood and bone. Connective tissue is comprised of cells separated by extracellular material made of organic and inorganic materials, such as the protein and mineral deposits of bone. Epithelial tissue covers the internal and external surfaces of organs inside the animal body and the external surface of the body of the organism.
SciQ
Most biochemical molecules are macromolecules, meaning that they are what?
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A) very small B) very dense C) very abundant D) very large
D) very large
Most biochemical molecules are macromolecules, meaning that they are very large. Some contain thousands of monomer molecules.
SciQ
The name of a spinal cord region corresponds to the level at which spinal nerves pass through the what?
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A) synovial fluid B) lumbar foramina C) intervertebral foramina D) notochord
C) intervertebral foramina
The Spinal Cord The description of the CNS is concentrated on the structures of the brain, but the spinal cord is another major organ of the system. Whereas the brain develops out of expansions of the neural tube into primary and then secondary vesicles, the spinal cord maintains the tube structure and is only specialized into certain regions. As the spinal cord continues to develop in the newborn, anatomical features mark its surface. The anterior midline is marked by the anterior median fissure, and the posterior midline is marked by the posterior median sulcus. Axons enter the posterior side through the dorsal (posterior) nerve root, which marks the posterolateral sulcus on either side. The axons emerging from the anterior side do so through the ventral (anterior) nerve root. Note that it is common to see the terms dorsal (dorsal = “back”) and ventral (ventral = “belly”) used interchangeably with posterior and anterior, particularly in reference to nerves and the structures of the spinal cord. You should learn to be comfortable with both. On the whole, the posterior regions are responsible for sensory functions and the anterior regions are associated with motor functions. This comes from the initial development of the spinal cord, which is divided into the basal plate and the alar plate. The basal plate is closest to the ventral midline of the neural tube, which will become the anterior face of the spinal cord and gives rise to motor neurons. The alar plate is on the dorsal side of the neural tube and gives rise to neurons that will receive sensory input from the periphery. The length of the spinal cord is divided into regions that correspond to the regions of the vertebral column. The name of a spinal cord region corresponds to the level at which spinal nerves pass through the intervertebral foramina. Immediately adjacent to the brain stem is the cervical region, followed by the thoracic, then the lumbar, and finally the sacral region. The spinal cord is not the full length of the vertebral column because the spinal cord does not grow significantly longer after the first or second year, but the skeleton continues to grow. The nerves that emerge from the spinal cord pass through the intervertebral formina at the respective levels. As the vertebral column grows, these nerves grow with it and result in a long bundle of nerves that resembles a horse’s tail and is named the cauda equina. The sacral spinal cord is at the level of the upper lumbar vertebral bones. The spinal nerves extend from their various levels to the proper level of the vertebral column.
SciQ
Tests for levels of what in blood allow a diabetic patient to regulate how much insulin to administer?
sciq_276
A) protein B) chloride C) alcohol D) glucose
D) glucose
Laboratory testing has come to the local drug store or grocery store because of developments in chemistry. You can test your blood glucose using a simple portable device that runs a chemical test on the blood sample and tells you how much glucose is present, allowing a diabetic patient to regulate how much insulin to administer (chemistry is also used to produce the insulin and the disposable syringe that administers the drug).
SciQ
The process of breaking down food into nutrients is known as __________
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A) filtration B) energy C) digestion D) absorption
C) digestion
As food is pushed through the GI tract by peristalsis, it undergoes digestion. Digestion is the process of breaking down food into nutrients. There are two types of digestion: mechanical digestion and chemical digestion.
SciQ
Reasoning can be broken down into two categories: deduction and?
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A) invention B) preduction C) conduction D) induction
D) induction
Any useful hypothesis will allow predictions based on reasoning. Reasoning can be broken down into two categories: deduction and induction. Most reasoning in science is formed through induction.
SciQ
What are used to make maps of the moon and other planets?
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A) imaging satellites B) rendering satellites C) topographical charts D) radio telescopes
A) imaging satellites
Astronomers use imaging satellites to study and make maps of the Moon and other planets.
SciQ
What term describes how closely packed the particles of matter are?
sciq_280
A) range B) density C) space D) mass
B) density
Density is an important physical property of matter. It reflects how closely packed the particles of matter are. When particles are packed together more tightly, matter has greater density. Differences in density of matter explain many phenomena, not just why helium balloons rise. For example, differences in density of cool and warm ocean water explain why currents such as the Gulf Stream flow through the oceans. You can see a colorful demonstration of substances with different densities at this URL:.
SciQ
Populations of viruses do not grow through cell division because they?
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A) Static B) Acidic C) non living D) are not cells
D) are not cells
Populations of viruses do not grow through cell division because they are not cells. Instead, they use the machinery and metabolism of a host cell to produce new copies of themselves. After infecting a host cell, a virion uses the cell’s ribosomes, enzymes, ATP, and other components to replicate. Viruses vary in how they do this. For example:.
SciQ
What is likely to happen to a parasite if it kills its host?
sciq_282
A) it mutates B) it dies C) it adapts D) it thrives
B) it dies
Some parasites kill their host, but most do not. It’s easy to see why. If a parasite kills its host, the parasite is also likely to die. Instead, parasites usually cause relatively minor damage to their host.
SciQ
What is a type of solid that lacks an ordered internal structure?
sciq_283
A) a sponge B) ice C) an amorphous solid D) an elastic solid
C) an amorphous solid
An amorphous solid is a solid that lacks an ordered internal structure.
SciQ
What is it called when you get the same result after repeating an experiment?
sciq_284
A) replication B) control C) variable D) initiation
A) replication
Getting the same result when an experiment is repeated is called replication. If research results can be replicated, it means they are more likely to be correct.
SciQ
What is the largest human organ?
sciq_285
A) lungs B) skin C) stomach D) brain
B) skin
human body system that includes the skin, nails, and hair.
SciQ
In the chest, the trachea divides as it enters the lungs to form the right and left what?
sciq_286
A) atrium B) ventricle C) alveoli D) bronchi
D) bronchi
In the chest, the trachea divides as it enters the lungs to form the right and left bronchi . The bronchi contain cartilage, which prevents them from collapsing. Mucus in the bronchi traps any remaining particles in air. Tiny, hair-like structures called cilia line the bronchi and sweep the particles and mucus toward the throat so they can be expelled from the body.
SciQ
Many objects have color because they contain what?
sciq_287
A) salts B) solvents C) pigments D) vitamins
C) pigments
Many objects have color because they contain pigments. A pigment is a substance that colors materials by reflecting light of certain wavelengths and absorbing light of other wavelengths. A very common pigment is the dark green pigment called chlorophyll, which is found in plants. Chlorophyll absorbs all but green wavelengths of visible light. Pigments are also found in many manufactured products. They are used to color paints, inks, and dyes. Just three pigments, called primary pigments, can be combined to produce all other colors. The primary colors of pigments are the same as the secondary colors of light: cyan, magenta, and yellow.
SciQ
What do craters and rifts become when the fill with water?
sciq_288
A) rivers B) creeks C) grasses D) lakes
D) lakes
Craters and rifts become lakes when they fill with water. Where does the water come from?.
SciQ
What is the long, narrow tube that carries food from the pharynx to the stomach by the mechanism of peristalsis?
sciq_290
A) esophagus B) liver C) gallbladder D) spinal cord
A) esophagus
The esophagus is a long, narrow tube that carries food from the pharynx to the stomach. It has no other purpose. Food moves through the esophagus because of peristalsis. At the lower end of the esophagus, a circular muscle, called a sphincter, controls the opening to the stomach. The sphincter relaxes to let food pass into the stomach. Then the sphincter contracts to prevent food from passing back into the esophagus.
SciQ
What is the temperature at which condensation of water vapor occurs called?
sciq_291
A) the tipping point B) the dew point C) the cooling point D) the boiling point
B) the dew point
The temperature at which condensation of water vapor occurs is called the dew point. The dew point varies depending on air temperature and moisture content.
SciQ
Alkenes have double bonds while alkynes have what?
sciq_292
A) triple bonds B) equal bonds C) quadruple bonds D) single bonds
A) triple bonds
Alkenes have double bonds; alkynes have triple bonds. Both undergo addition reactions.
SciQ
What is our main source of aluminum ore?
sciq_293
A) coal B) tin C) cobalt D) bauxite
D) bauxite
Weathering may concentrate some resources. In tropical climates, chemical weathering can be intense. Some minerals dissolve and water carries them away. This leaves behind the materials that are not soluble. Bauxite is aluminum oxide that collects this way. Bauxite is our main source of aluminum ore.
SciQ
What are the 2 primary hosts of ebola in central africa?
sciq_294
A) hyenas and apes B) apes and bats C) apes and hippos D) lions and elephants
B) apes and bats
Several lethal viruses that cause viral hemorrhagic fever have been discovered, two of which are shown in the Figure below . Ebola outbreaks have been limited mainly to remote areas of the world. However, they have gained extensive media attention because of the high mortality rate—23 percent to 90 percent—depending on the strain. The primary hosts of the viruses are thought to be apes in west central Africa, but the virus has also been isolated from bats in the same region.
SciQ
Unlike prokaryotic cells, dna and rna synthesis in eukaryotic cells occurs in a separate compartment from synthesis of what?
sciq_295
A) phenotype B) membrane C) protein D) acids
C) protein
In eukaryotic cells, DNA and RNA synthesis occur in a separate compartment from protein synthesis. In prokaryotic cells, both processes occur together. What advantages might there be to separating the processes? What advantages might there be to having them occur together? The size of the genome in one of the most well-studied prokaryotes, E. coli, is 4.6 million base pairs (approximately 1.1 mm, if cut and stretched out). So how does this fit inside a small bacterial cell? The DNA is twisted by what is known as supercoiling. Supercoiling means that DNA is either under-wound (less than one turn of the helix per 10 base pairs) or over-wound (more than 1 turn per 10 base pairs) from its normal relaxed state. Some proteins are known to be involved in the supercoiling; other proteins and enzymes such as DNA gyrase help in maintaining the supercoiled structure. Eukaryotes, whose chromosomes each consist of a linear DNA molecule, employ a different type of packing strategy to fit their DNA inside the nucleus (Figure 14.11). At the most basic level, DNA is wrapped around proteins known as histones to form structures called nucleosomes. The histones are evolutionarily conserved proteins that are rich in basic amino acids and form an octamer. The DNA (which is negatively charged because of the phosphate groups) is wrapped tightly around the histone core. This nucleosome is linked to the next one with the help of a linker DNA. This is also known as the “beads on a string” structure. This is further compacted into a 30 nm fiber, which is the diameter of the structure. At the metaphase stage, the chromosomes are at their most compact, are approximately 700 nm in width, and are found in association with scaffold proteins. In interphase, eukaryotic chromosomes have two distinct regions that can be distinguished by staining. The tightly packaged region is known as heterochromatin, and the less dense region is known as euchromatin. Heterochromatin usually contains genes that are not expressed, and is found in the regions of the centromere and telomeres. The euchromatin usually contains genes that are transcribed, with DNA packaged around nucleosomes but not further compacted.
SciQ
What important organelle (that would otherwise be centrally located and crucial to the cell's survival) do prokaryotic cells lack?
sciq_296
A) nucleus B) electrons C) protons D) molecules
A) nucleus
Cell division is simpler in prokaryotes than eukaryotes because prokaryotic cells themselves are simpler. Prokaryotic cells have a single circular chromosome, no nucleus, and few other organelles. Eukaryotic cells, in contrast, have multiple chromosomes contained within a nucleus, and many other organelles. All of these cell parts must be duplicated and then separated when the cell divides. A chromosome is a molecule of DNA, and will be the focus of a subsequent concept.
SciQ
What occurs when some members of a species become geographically separated?
sciq_298
A) allopatric speciation B) symbiotic speciation C) reflective speciation D) divergent speciation
A) allopatric speciation
New species arise in the process of speciation. Allopatric speciation occurs when some members of a species become geographically separated. They then evolve genetic differences. If the differences prevent them from interbreeding with the original species, a new species has evolved. Sympatric speciation occurs without geographic separation.
SciQ
What creatures evolved from a lobe-finned lungfish ancestor?
sciq_299
A) birds B) mice C) horses D) amphibians
D) amphibians
Fossil evidence shows that amphibians evolved about 365 million years ago from a lobe-finned lungfish ancestor. As the earliest land vertebrates, they were highly successful. Some of them were much larger than today’s amphibians. For more than 100 million years, amphibians remained the dominant land vertebrates. Then some of them evolved into reptiles. Once reptiles appeared, with their amniotic eggs, they replaced amphibians as the dominant land vertebrates.
SciQ
What is the term for a mixture of two or more substances that has the same composition throughout?
sciq_300
A) fluid B) solution C) structure D) simple liquid
B) solution
Water is the main ingredient of many solutions. A solution is a mixture of two or more substances that has the same composition throughout. Some solutions are acids and some are bases. To understand acids and bases, you need to know more about pure water. In pure water (such as distilled water), a tiny fraction of water molecules naturally breaks down to form ions. An ion is an electrically charged atom or molecule. The breakdown of water is represented by the chemical equation.
SciQ
What are flagellate protozoa that cause giardiasis?
sciq_301
A) plankton B) diatoms C) fungus D) giardia
D) giardia
Giardia are flagellate protozoa that cause giardiasis . The parasites enter the body through food or water that has been contaminated by feces of infected people or animals. The protozoa attach to the lining of the host’s small intestine, where they prevent the host from fully absorbing nutrients. They may also cause diarrhea, abdominal pain, and fever. A picture of a Giardia protozoan opens this concept.
SciQ
Rna and dna are types of what biochemical compounds containing the elements carbon, hydrogen, oxygen, nitrogen, and phosphorus?
sciq_302
A) amino acids B) hormones C) nucleic acids D) nitrous acids
C) nucleic acids
Nucleic acids are one of four classes of biochemical compounds. (The other three classes are carbohydrates, proteins, and lipids. ) Nucleic acids include RNA (ribonucleic acid) as well as DNA (deoxyribonucleic acid). Both types of nucleic acids contain the elements carbon, hydrogen, oxygen, nitrogen, and phosphorus.
SciQ
What are the contacts between neurons called?
sciq_303
A) electrodes B) synapses C) impulses D) neurapses
B) synapses
12.5 Communication Between Neurons The basis of the electrical signal within a neuron is the action potential that propagates down the axon. For a neuron to generate an action potential, it needs to receive input from another source, either another neuron or a sensory stimulus. That input will result in opening ion channels in the neuron, resulting in a graded potential based on the strength of the stimulus. Graded potentials can be depolarizing or hyperpolarizing and can summate to affect the probability of the neuron reaching threshold. Graded potentials can be the result of sensory stimuli. If the sensory stimulus is received by the dendrites of a unipolar sensory neuron, such as the sensory neuron ending in the skin, the graded potential is called a generator potential because it can directly generate the action potential in the initial segment of the axon. If the sensory stimulus is received by a specialized sensory receptor cell, the graded potential is called a receptor potential. Graded potentials produced by interactions between neurons at synapses are called postsynaptic potentials (PSPs). A depolarizing graded potential at a synapse is called an excitatory PSP, and a hyperpolarizing graded potential at a synapse is called an inhibitory PSP. Synapses are the contacts between neurons, which can either be chemical or electrical in nature. Chemical synapses are far more common. At a chemical synapse, neurotransmitter is released from the presynaptic element and diffuses across the synaptic cleft. The neurotransmitter binds to a receptor protein and causes a change in the postsynaptic membrane (the PSP). The neurotransmitter must be inactivated or removed from the synaptic cleft so that the stimulus is limited in time. The particular characteristics of a synapse vary based on the neurotransmitter system produced by that neuron. The cholinergic system is found at the neuromuscular junction and in certain places within the nervous system. Amino acids, such as glutamate, glycine, and gamma-aminobutyric acid (GABA) are used as neurotransmitters. Other neurotransmitters are the result of amino acids being enzymatically changed, as in the biogenic amines, or being covalently bonded together, as in the neuropeptides.
SciQ
What is the color of the powder of a mineral?
sciq_304
A) organic B) streak C) gray D) blue
B) streak
Streak is the color of the powder of a mineral. To do a streak test, you scrape the mineral across an unglazed porcelain plate. The plate is harder than many minerals, causing the minerals to leave a streak of powder on the plate. The color of the streak often differs from the color of the larger mineral sample, as Figure below shows.
SciQ
What type of compound is essential to life?
sciq_305
A) oxygen B) water C) nitrogen D) carbon
B) water
Water is essential to life because chemical reactions within cells take place in water. Most people can survive only a few days without consuming water to replace their water losses. How do you lose water?.
SciQ
Which part of the ear amplifies the sound waves?
sciq_306
A) eardrum B) ear canal C) cochlea D) middle ear
D) middle ear
The outer ear catches sound waves and funnels them to the middle ear. The middle ear amplifies the sound waves and passes them to the inner ear. The inner ear changes the sound waves to electrical signals. The signals travel to the brain, which interprets the sounds.
SciQ
The shape of a virus is determined by the type and arrangement of proteins in its what?
sciq_307
A) enamel B) nuclei C) anode D) capsid
D) capsid
22.1 Introduction Viruses are the smallest biological particle (the tiniest are only 20 nm in diameter). However, they are not biological organisms so they are not classified in any kingdom of living things. They do not have any organelles and cannot respire or perform metabolic functions. Viruses are merely strands of DNA or RNA surrounded by a protective protein coat called a capsid. Viruses only come to life when they have invaded a cell. Outside of a host cell, viruses are completely inert. Since first being identified in 1935, viruses have been classified into more than 160 major groups. Viruses are classified based on their shape, replication properties, and the diseases that they cause. Furthermore, the shape of a virus is determined by the type and arrangement of proteins in its capsid. Viruses pathogenic to humans are currently classified into 21 groups. Viruses can also attack bacteria and infect bacterial cells. Such viruses are called bacteriophages.
SciQ
What is the rising and sinking of warm and cooler material called?
sciq_308
A) conveyance B) convection C) diffusion D) depression
B) convection
Hot lower mantle material rises upward ( Figure below ). As it rises, it cools. At the top of the mantle it moves horizontally. Over time it becomes cool and dense enough that it sinks. Back at the bottom of the mantle, it travels horizontally. Eventually the material gets to the location where warm mantle material is rising. The rising and sinking of warm and cooler material is called convection .
SciQ
What is a group of connected cells that have a similar function within an organism called?
sciq_309
A) colony B) nucleus C) organ D) tissue
D) tissue
A tissue is a group of connected cells that have a similar function within an organism. More complex organisms such as jellyfish, coral, and sea anemones have a tissue level of organization. For example, jellyfish have tissues that have separate protective, digestive, and sensory functions.
SciQ
The number of what subatomic particles can vary between atoms of the same element?
sciq_310
A) neutrons B) neurons C) electrons D) protons
A) neutrons
As stated earlier, not all atoms of a given element are identical. Specifically, the number of neutrons in the nucleus can vary for many elements. As an example, naturally occurring carbon exists in three forms, which are illustrated in Figure below .
SciQ
Water is recycled constantly through which system?
sciq_311
A) the hydropshere B) the troposphere C) the ecosystem D) the habitat
C) the ecosystem
Water is recycled constantly through the ecosystem. That means any water you drank today has been around for millions of years. You could be drinking water that was once drunk by George Washington, the first humans, or even the dinosaurs.
SciQ
The process in which organ systems work to maintain a stable internal environment is called what?
sciq_312
A) thrombosis B) homeostasis C) consciousness D) ketosis
B) homeostasis
The process in which organ systems work to maintain a stable internal environment is called homeostasis . Keeping a stable internal environment requires constant adjustments. Here are just three of the many ways that human organ systems help the body maintain homeostasis:.
SciQ
What do scientist's believe mercury's core is mostly made of?
sciq_313
A) water B) quicksilver C) melted iron D) helium gas
C) melted iron
Figure below shows a diagram of Mercury’s interior. Mercury is one of the densest planets. Scientists think that the interior contains a large core made mostly of melted iron. Mercury's core takes up about 42% of the planet's volume. Mercury's highly cratered surface is evidence that Mercury is not geologically active.
SciQ